1 /*
   2  * Copyright (c) 2008, 2020, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.lang.invoke;
  27 
  28 import sun.invoke.util.BytecodeDescriptor;
  29 import sun.invoke.util.VerifyAccess;
  30 
  31 import java.lang.reflect.Constructor;
  32 import java.lang.reflect.Field;
  33 import java.lang.reflect.Member;
  34 import java.lang.reflect.Method;
  35 import java.lang.reflect.Modifier;
  36 import java.util.ArrayList;
  37 import java.util.Collections;
  38 import java.util.Iterator;
  39 import java.util.List;
  40 import java.util.Objects;
  41 
  42 import static java.lang.invoke.MethodHandleNatives.Constants.*;
  43 import static java.lang.invoke.MethodHandleStatics.newIllegalArgumentException;
  44 import static java.lang.invoke.MethodHandleStatics.newInternalError;
  45 
  46 /**
  47  * A {@code MemberName} is a compact symbolic datum which fully characterizes
  48  * a method or field reference.
  49  * A member name refers to a field, method, constructor, or member type.
  50  * Every member name has a simple name (a string) and a type (either a Class or MethodType).
  51  * A member name may also have a non-null declaring class, or it may be simply
  52  * a naked name/type pair.
  53  * A member name may also have non-zero modifier flags.
  54  * Finally, a member name may be either resolved or unresolved.
  55  * If it is resolved, the existence of the named member has been determined by the JVM.
  56  * <p>
  57  * Whether resolved or not, a member name provides no access rights or
  58  * invocation capability to its possessor.  It is merely a compact
  59  * representation of all symbolic information necessary to link to
  60  * and properly use the named member.
  61  * <p>
  62  * When resolved, a member name's internal implementation may include references to JVM metadata.
  63  * This representation is stateless and only descriptive.
  64  * It provides no private information and no capability to use the member.
  65  * <p>
  66  * By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
  67  * about the internals of a method (except its bytecodes) and also
  68  * allows invocation.  A MemberName is much lighter than a Method,
  69  * since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
  70  * and those seven fields omit much of the information in Method.
  71  * @author jrose
  72  */
  73 /*non-public*/
  74 final class ResolvedMethodName {
  75     //@Injected JVM_Method* vmtarget;
  76     //@Injected Class<?>    vmholder;
  77 };
  78 
  79 /*non-public*/
  80 final class MemberName implements Member, Cloneable {
  81     private Class<?> clazz;       // class in which the member is defined
  82     private String   name;        // may be null if not yet materialized
  83     private Object   type;        // may be null if not yet materialized
  84     private int      flags;       // modifier bits; see reflect.Modifier
  85     private ResolvedMethodName method;    // cached resolved method information
  86     //@Injected intptr_t       vmindex;   // vtable index or offset of resolved member
  87     Object   resolution;  // if null, this guy is resolved
  88 
  89     /** Return the declaring class of this member.
  90      *  In the case of a bare name and type, the declaring class will be null.
  91      */
  92     public Class<?> getDeclaringClass() {
  93         return clazz;
  94     }
  95 
  96     /** Utility method producing the class loader of the declaring class. */
  97     public ClassLoader getClassLoader() {
  98         return clazz.getClassLoader();
  99     }
 100 
 101     /** Return the simple name of this member.
 102      *  For a type, it is the same as {@link Class#getSimpleName}.
 103      *  For a method or field, it is the simple name of the member.
 104      *  For a constructor, it is always {@code "<init>"}.
 105      */
 106     public String getName() {
 107         if (name == null) {
 108             expandFromVM();
 109             if (name == null) {
 110                 return null;
 111             }
 112         }
 113         return name;
 114     }
 115 
 116     public MethodType getMethodOrFieldType() {
 117         if (isInvocable())
 118             return getMethodType();
 119         if (isGetter())
 120             return MethodType.methodType(getFieldType());
 121         if (isSetter())
 122             return MethodType.methodType(void.class, getFieldType());
 123         throw new InternalError("not a method or field: "+this);
 124     }
 125 
 126     /** Return the declared type of this member, which
 127      *  must be a method or constructor.
 128      */
 129     public MethodType getMethodType() {
 130         if (type == null) {
 131             expandFromVM();
 132             if (type == null) {
 133                 return null;
 134             }
 135         }
 136         if (!isInvocable()) {
 137             throw newIllegalArgumentException("not invocable, no method type");
 138         }
 139 
 140         {
 141             // Get a snapshot of type which doesn't get changed by racing threads.
 142             final Object type = this.type;
 143             if (type instanceof MethodType) {
 144                 return (MethodType) type;
 145             }
 146         }
 147 
 148         // type is not a MethodType yet.  Convert it thread-safely.
 149         synchronized (this) {
 150             if (type instanceof String sig) {
 151                 MethodType res = MethodType.fromDescriptor(sig, getClassLoader());
 152                 type = res;
 153             } else if (type instanceof Object[] typeInfo) {
 154                 Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
 155                 Class<?> rtype = (Class<?>) typeInfo[0];
 156                 MethodType res = MethodType.makeImpl(rtype, ptypes, true);
 157                 type = res;
 158             }
 159             // Make sure type is a MethodType for racing threads.
 160             assert type instanceof MethodType : "bad method type " + type;
 161         }
 162         return (MethodType) type;
 163     }
 164 
 165     /** Return the descriptor of this member, which
 166      *  must be a method or constructor.
 167      */
 168     String getMethodDescriptor() {
 169         if (type == null) {
 170             expandFromVM();
 171             if (type == null) {
 172                 return null;
 173             }
 174         }
 175         if (!isInvocable()) {
 176             throw newIllegalArgumentException("not invocable, no method type");
 177         }
 178 
 179         // Get a snapshot of type which doesn't get changed by racing threads.
 180         final Object type = this.type;
 181         if (type instanceof String) {
 182             return (String) type;
 183         } else {
 184             return getMethodType().toMethodDescriptorString();
 185         }
 186     }
 187 
 188     /** Return the actual type under which this method or constructor must be invoked.
 189      *  For non-static methods or constructors, this is the type with a leading parameter,
 190      *  a reference to declaring class.  For static methods, it is the same as the declared type.
 191      */
 192     public MethodType getInvocationType() {
 193         MethodType itype = getMethodOrFieldType();
 194         if (isConstructor() && getReferenceKind() == REF_newInvokeSpecial)
 195             return itype.changeReturnType(clazz);
 196         if (!isStatic())
 197             return itype.insertParameterTypes(0, clazz);
 198         return itype;
 199     }
 200 
 201     /** Utility method producing the parameter types of the method type. */
 202     public Class<?>[] getParameterTypes() {
 203         return getMethodType().parameterArray();
 204     }
 205 
 206     /** Utility method producing the return type of the method type. */
 207     public Class<?> getReturnType() {
 208         return getMethodType().returnType();
 209     }
 210 
 211     /** Return the declared type of this member, which
 212      *  must be a field or type.
 213      *  If it is a type member, that type itself is returned.
 214      */
 215     public Class<?> getFieldType() {
 216         if (type == null) {
 217             expandFromVM();
 218             if (type == null) {
 219                 return null;
 220             }
 221         }
 222         if (isInvocable()) {
 223             throw newIllegalArgumentException("not a field or nested class, no simple type");
 224         }
 225 
 226         {
 227             // Get a snapshot of type which doesn't get changed by racing threads.
 228             final Object type = this.type;
 229             if (type instanceof Class<?>) {
 230                 return (Class<?>) type;
 231             }
 232         }
 233 
 234         // type is not a Class yet.  Convert it thread-safely.
 235         synchronized (this) {
 236             if (type instanceof String sig) {
 237                 MethodType mtype = MethodType.fromDescriptor("()"+sig, getClassLoader());
 238                 Class<?> res = mtype.returnType();
 239                 type = res;
 240             }
 241             // Make sure type is a Class for racing threads.
 242             assert type instanceof Class<?> : "bad field type " + type;
 243         }
 244         return (Class<?>) type;
 245     }
 246 
 247     /** Utility method to produce either the method type or field type of this member. */
 248     public Object getType() {
 249         return (isInvocable() ? getMethodType() : getFieldType());
 250     }
 251 
 252     /** Utility method to produce the signature of this member,
 253      *  used within the class file format to describe its type.
 254      */
 255     public String getSignature() {
 256         if (type == null) {
 257             expandFromVM();
 258             if (type == null) {
 259                 return null;
 260             }
 261         }
 262         if (isInvocable())
 263             return BytecodeDescriptor.unparse(getMethodType());
 264         else
 265             return BytecodeDescriptor.unparse(getFieldType());
 266     }
 267 
 268     /** Return the modifier flags of this member.
 269      *  @see java.lang.reflect.Modifier
 270      */
 271     public int getModifiers() {
 272         return (flags & RECOGNIZED_MODIFIERS);
 273     }
 274 
 275     /** Return the reference kind of this member, or zero if none.
 276      */
 277     public byte getReferenceKind() {
 278         return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK);
 279     }
 280     private boolean referenceKindIsConsistent() {
 281         byte refKind = getReferenceKind();
 282         if (refKind == REF_NONE)  return isType();
 283         if (isField()) {
 284             assert(staticIsConsistent());
 285             assert(MethodHandleNatives.refKindIsField(refKind));
 286         } else if (isConstructor()) {
 287             assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial);
 288         } else if (isMethod()) {
 289             assert(staticIsConsistent());
 290             assert(MethodHandleNatives.refKindIsMethod(refKind));
 291             if (clazz.isInterface())
 292                 assert(refKind == REF_invokeInterface ||
 293                        refKind == REF_invokeStatic    ||
 294                        refKind == REF_invokeSpecial   ||
 295                        refKind == REF_invokeVirtual && isObjectPublicMethod());
 296         } else {
 297             assert(false);
 298         }
 299         return true;
 300     }
 301     private boolean isObjectPublicMethod() {
 302         if (clazz == Object.class)  return true;
 303         MethodType mtype = getMethodType();
 304         if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0)
 305             return true;
 306         if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0)
 307             return true;
 308         if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class)
 309             return true;
 310         return false;
 311     }
 312 
 313     /*non-public*/
 314     boolean referenceKindIsConsistentWith(int originalRefKind) {
 315         int refKind = getReferenceKind();
 316         if (refKind == originalRefKind) return true;
 317         if (getClass().desiredAssertionStatus()) {
 318             switch (originalRefKind) {
 319                 case REF_invokeInterface -> {
 320                     // Looking up an interface method, can get (e.g.) Object.hashCode
 321                     assert (refKind == REF_invokeVirtual || refKind == REF_invokeSpecial) : this;
 322                 }
 323                 case REF_invokeVirtual, REF_newInvokeSpecial -> {
 324                     // Looked up a virtual, can get (e.g.) final String.hashCode.
 325                     assert (refKind == REF_invokeSpecial) : this;
 326                 }
 327                 default -> {
 328                     assert (false) : this + " != " + MethodHandleNatives.refKindName((byte) originalRefKind);
 329                 }
 330             }
 331         }
 332         return true;
 333     }
 334     private boolean staticIsConsistent() {
 335         byte refKind = getReferenceKind();
 336         return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0;
 337     }
 338     private boolean vminfoIsConsistent() {
 339         byte refKind = getReferenceKind();
 340         assert(isResolved());  // else don't call
 341         Object vminfo = MethodHandleNatives.getMemberVMInfo(this);
 342         assert(vminfo instanceof Object[]);
 343         long vmindex = (Long) ((Object[])vminfo)[0];
 344         Object vmtarget = ((Object[])vminfo)[1];
 345         if (MethodHandleNatives.refKindIsField(refKind)) {
 346             assert(vmindex >= 0) : vmindex + ":" + this;
 347             assert(vmtarget instanceof Class);
 348         } else {
 349             if (MethodHandleNatives.refKindDoesDispatch(refKind))
 350                 assert(vmindex >= 0) : vmindex + ":" + this;
 351             else
 352                 assert(vmindex < 0) : vmindex;
 353             assert(vmtarget instanceof MemberName) : vmtarget + " in " + this;
 354         }
 355         return true;
 356     }
 357 
 358     private MemberName changeReferenceKind(byte refKind, byte oldKind) {
 359         assert(getReferenceKind() == oldKind);
 360         assert(MethodHandleNatives.refKindIsValid(refKind));
 361         flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT);
 362         return this;
 363     }
 364 
 365     private boolean testFlags(int mask, int value) {
 366         return (flags & mask) == value;
 367     }
 368     private boolean testAllFlags(int mask) {
 369         return testFlags(mask, mask);
 370     }
 371     private boolean testAnyFlags(int mask) {
 372         return !testFlags(mask, 0);
 373     }
 374 
 375     /** Utility method to query if this member is a method handle invocation (invoke or invokeExact).
 376      */
 377     public boolean isMethodHandleInvoke() {
 378         final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
 379         final int negs = Modifier.STATIC;
 380         if (testFlags(bits | negs, bits) &&
 381             clazz == MethodHandle.class) {
 382             return isMethodHandleInvokeName(name);
 383         }
 384         return false;
 385     }
 386     public static boolean isMethodHandleInvokeName(String name) {
 387         switch (name) {
 388         case "invoke":
 389         case "invokeExact":
 390             return true;
 391         default:
 392             return false;
 393         }
 394     }
 395     public boolean isVarHandleMethodInvoke() {
 396         final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
 397         final int negs = Modifier.STATIC;
 398         if (testFlags(bits | negs, bits) &&
 399             clazz == VarHandle.class) {
 400             return isVarHandleMethodInvokeName(name);
 401         }
 402         return false;
 403     }
 404     public static boolean isVarHandleMethodInvokeName(String name) {
 405         try {
 406             VarHandle.AccessMode.valueFromMethodName(name);
 407             return true;
 408         } catch (IllegalArgumentException e) {
 409             return false;
 410         }
 411     }
 412     private static final int MH_INVOKE_MODS = Modifier.NATIVE | Modifier.FINAL | Modifier.PUBLIC;
 413 
 414     /** Utility method to query the modifier flags of this member. */
 415     public boolean isStatic() {
 416         return Modifier.isStatic(flags);
 417     }
 418     /** Utility method to query the modifier flags of this member. */
 419     public boolean isPublic() {
 420         return Modifier.isPublic(flags);
 421     }
 422     /** Utility method to query the modifier flags of this member. */
 423     public boolean isPrivate() {
 424         return Modifier.isPrivate(flags);
 425     }
 426     /** Utility method to query the modifier flags of this member. */
 427     public boolean isProtected() {
 428         return Modifier.isProtected(flags);
 429     }
 430     /** Utility method to query the modifier flags of this member. */
 431     public boolean isFinal() {
 432         return Modifier.isFinal(flags);
 433     }
 434     /** Utility method to query whether this member or its defining class is final. */
 435     public boolean canBeStaticallyBound() {
 436         return Modifier.isFinal(flags | clazz.getModifiers());
 437     }
 438     /** Utility method to query the modifier flags of this member. */
 439     public boolean isVolatile() {
 440         return Modifier.isVolatile(flags);
 441     }
 442     /** Utility method to query the modifier flags of this member. */
 443     public boolean isAbstract() {
 444         return Modifier.isAbstract(flags);
 445     }
 446     /** Utility method to query the modifier flags of this member. */
 447     public boolean isNative() {
 448         return Modifier.isNative(flags);
 449     }
 450     // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo
 451 
 452     // unofficial modifier flags, used by HotSpot:
 453     static final int BRIDGE    = 0x00000040;
 454     static final int VARARGS   = 0x00000080;
 455     static final int SYNTHETIC = 0x00001000;
 456     static final int ANNOTATION= 0x00002000;
 457     static final int ENUM      = 0x00004000;
 458     /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
 459     public boolean isBridge() {
 460         return testAllFlags(IS_METHOD | BRIDGE);
 461     }
 462     /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
 463     public boolean isVarargs() {
 464         return testAllFlags(VARARGS) && isInvocable();
 465     }
 466     /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
 467     public boolean isSynthetic() {
 468         return testAllFlags(SYNTHETIC);
 469     }
 470 
 471     static final String CONSTRUCTOR_NAME = "<init>";  // the ever-popular
 472 
 473     // modifiers exported by the JVM:
 474     static final int RECOGNIZED_MODIFIERS = 0xFFFF;
 475 
 476     // private flags, not part of RECOGNIZED_MODIFIERS:
 477     static final int
 478             IS_METHOD        = MN_IS_METHOD,        // method (not constructor)
 479             IS_CONSTRUCTOR   = MN_IS_CONSTRUCTOR,   // constructor
 480             IS_FIELD         = MN_IS_FIELD,         // field
 481             IS_TYPE          = MN_IS_TYPE,          // nested type
 482             CALLER_SENSITIVE = MN_CALLER_SENSITIVE, // @CallerSensitive annotation detected
 483             TRUSTED_FINAL    = MN_TRUSTED_FINAL;    // trusted final field
 484 
 485     static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;
 486     static final int ALL_KINDS = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE;
 487     static final int IS_INVOCABLE = IS_METHOD | IS_CONSTRUCTOR;
 488     static final int IS_FIELD_OR_METHOD = IS_METHOD | IS_FIELD;
 489     static final int SEARCH_ALL_SUPERS = MN_SEARCH_SUPERCLASSES | MN_SEARCH_INTERFACES;
 490 
 491     /** Utility method to query whether this member is a method or constructor. */
 492     public boolean isInvocable() {
 493         return testAnyFlags(IS_INVOCABLE);
 494     }
 495     /** Utility method to query whether this member is a method, constructor, or field. */
 496     public boolean isFieldOrMethod() {
 497         return testAnyFlags(IS_FIELD_OR_METHOD);
 498     }
 499     /** Query whether this member is a method. */
 500     public boolean isMethod() {
 501         return testAllFlags(IS_METHOD);
 502     }
 503     /** Query whether this member is a constructor. */
 504     public boolean isConstructor() {
 505         return testAllFlags(IS_CONSTRUCTOR);
 506     }
 507     /** Query whether this member is a field. */
 508     public boolean isField() {
 509         return testAllFlags(IS_FIELD);
 510     }
 511     /** Query whether this member is a type. */
 512     public boolean isType() {
 513         return testAllFlags(IS_TYPE);
 514     }
 515     /** Utility method to query whether this member is neither public, private, nor protected. */
 516     public boolean isPackage() {
 517         return !testAnyFlags(ALL_ACCESS);
 518     }
 519     /** Query whether this member has a CallerSensitive annotation. */
 520     public boolean isCallerSensitive() {
 521         return testAllFlags(CALLER_SENSITIVE);
 522     }
 523     /** Query whether this member is a trusted final field. */
 524     public boolean isTrustedFinalField() { return testAllFlags(TRUSTED_FINAL|IS_FIELD); }
 525 
 526     /** Utility method to query whether this member is accessible from a given lookup class. */
 527     public boolean isAccessibleFrom(Class<?> lookupClass) {
 528         int mode = (ALL_ACCESS|MethodHandles.Lookup.PACKAGE|MethodHandles.Lookup.MODULE);
 529         return VerifyAccess.isMemberAccessible(this.getDeclaringClass(), this.getDeclaringClass(), flags,
 530                                                lookupClass, null, mode);
 531     }
 532 
 533     /**
 534      * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
 535      */
 536     public boolean refersTo(Class<?> declc, String n) {
 537         return clazz == declc && getName().equals(n);
 538     }
 539 
 540     /** Initialize a query.   It is not resolved. */
 541     private void init(Class<?> defClass, String name, Object type, int flags) {
 542         // defining class is allowed to be null (for a naked name/type pair)
 543         //name.toString();  // null check
 544         //type.equals(type);  // null check
 545         // fill in fields:
 546         this.clazz = defClass;
 547         this.name = name;
 548         this.type = type;
 549         this.flags = flags;
 550         assert(testAnyFlags(ALL_KINDS));
 551         assert(this.resolution == null);  // nobody should have touched this yet
 552         //assert(referenceKindIsConsistent());  // do this after resolution
 553     }
 554 
 555     /**
 556      * Calls down to the VM to fill in the fields.  This method is
 557      * synchronized to avoid racing calls.
 558      */
 559     private void expandFromVM() {
 560         if (type != null) {
 561             return;
 562         }
 563         if (!isResolved()) {
 564             return;
 565         }
 566         MethodHandleNatives.expand(this);
 567     }
 568 
 569     // Capturing information from the Core Reflection API:
 570     private static int flagsMods(int flags, int mods, byte refKind) {
 571         assert((flags & RECOGNIZED_MODIFIERS) == 0);
 572         assert((mods & ~RECOGNIZED_MODIFIERS) == 0);
 573         assert((refKind & ~MN_REFERENCE_KIND_MASK) == 0);
 574         return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
 575     }
 576     /** Create a name for the given reflected method.  The resulting name will be in a resolved state. */
 577     public MemberName(Method m) {
 578         this(m, false);
 579     }
 580     @SuppressWarnings("LeakingThisInConstructor")
 581     public MemberName(Method m, boolean wantSpecial) {
 582         Objects.requireNonNull(m);
 583         // fill in vmtarget, vmindex while we have m in hand:
 584         MethodHandleNatives.init(this, m);
 585         if (clazz == null) {  // MHN.init failed
 586             if (m.getDeclaringClass() == MethodHandle.class &&
 587                 isMethodHandleInvokeName(m.getName())) {
 588                 // The JVM did not reify this signature-polymorphic instance.
 589                 // Need a special case here.
 590                 // See comments on MethodHandleNatives.linkMethod.
 591                 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
 592                 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
 593                 init(MethodHandle.class, m.getName(), type, flags);
 594                 if (isMethodHandleInvoke())
 595                     return;
 596             }
 597             if (m.getDeclaringClass() == VarHandle.class &&
 598                 isVarHandleMethodInvokeName(m.getName())) {
 599                 // The JVM did not reify this signature-polymorphic instance.
 600                 // Need a special case here.
 601                 // See comments on MethodHandleNatives.linkMethod.
 602                 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
 603                 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
 604                 init(VarHandle.class, m.getName(), type, flags);
 605                 if (isVarHandleMethodInvoke())
 606                     return;
 607             }
 608             throw new LinkageError(m.toString());
 609         }
 610         assert(isResolved() && this.clazz != null);
 611         this.name = m.getName();
 612         if (this.type == null)
 613             this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
 614         if (wantSpecial) {
 615             if (isAbstract())
 616                 throw new AbstractMethodError(this.toString());
 617             if (getReferenceKind() == REF_invokeVirtual)
 618                 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
 619             else if (getReferenceKind() == REF_invokeInterface)
 620                 // invokeSpecial on a default method
 621                 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
 622         }
 623     }
 624     public MemberName asSpecial() {
 625         switch (getReferenceKind()) {
 626         case REF_invokeSpecial:     return this;
 627         case REF_invokeVirtual:     return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
 628         case REF_invokeInterface:   return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
 629         case REF_newInvokeSpecial:  return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
 630         }
 631         throw new IllegalArgumentException(this.toString());
 632     }
 633     /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
 634      *  In that case it must already be REF_invokeSpecial.
 635      */
 636     public MemberName asConstructor() {
 637         switch (getReferenceKind()) {
 638         case REF_invokeSpecial:     return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
 639         case REF_newInvokeSpecial:  return this;
 640         }
 641         throw new IllegalArgumentException(this.toString());
 642     }
 643     /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind
 644      *  REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface.
 645      *  The end result is to get a fully virtualized version of the MN.
 646      *  (Note that resolving in the JVM will sometimes devirtualize, changing
 647      *  REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface
 648      *  in some corner cases to either of the previous two; this transform
 649      *  undoes that change under the assumption that it occurred.)
 650      */
 651     public MemberName asNormalOriginal() {
 652         byte normalVirtual = clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
 653         byte refKind = getReferenceKind();
 654         byte newRefKind = refKind;
 655         MemberName result = this;
 656         switch (refKind) {
 657         case REF_invokeInterface:
 658         case REF_invokeVirtual:
 659         case REF_invokeSpecial:
 660             newRefKind = normalVirtual;
 661             break;
 662         }
 663         if (newRefKind == refKind)
 664             return this;
 665         result = clone().changeReferenceKind(newRefKind, refKind);
 666         assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
 667         return result;
 668     }
 669     /** Create a name for the given reflected constructor.  The resulting name will be in a resolved state. */
 670     @SuppressWarnings("LeakingThisInConstructor")
 671     public MemberName(Constructor<?> ctor) {
 672         Objects.requireNonNull(ctor);
 673         // fill in vmtarget, vmindex while we have ctor in hand:
 674         MethodHandleNatives.init(this, ctor);
 675         assert(isResolved() && this.clazz != null);
 676         this.name = CONSTRUCTOR_NAME;
 677         if (this.type == null)
 678             this.type = new Object[] { void.class, ctor.getParameterTypes() };
 679     }
 680     /** Create a name for the given reflected field.  The resulting name will be in a resolved state.
 681      */
 682     public MemberName(Field fld) {
 683         this(fld, false);
 684     }
 685     @SuppressWarnings("LeakingThisInConstructor")
 686     public MemberName(Field fld, boolean makeSetter) {
 687         Objects.requireNonNull(fld);
 688         // fill in vmtarget, vmindex while we have fld in hand:
 689         MethodHandleNatives.init(this, fld);
 690         assert(isResolved() && this.clazz != null);
 691         this.name = fld.getName();
 692         this.type = fld.getType();
 693         assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
 694         byte refKind = this.getReferenceKind();
 695         assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
 696         if (makeSetter) {
 697             changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
 698         }
 699     }
 700     public boolean isGetter() {
 701         return MethodHandleNatives.refKindIsGetter(getReferenceKind());
 702     }
 703     public boolean isSetter() {
 704         return MethodHandleNatives.refKindIsSetter(getReferenceKind());
 705     }
 706     public MemberName asSetter() {
 707         byte refKind = getReferenceKind();
 708         assert(MethodHandleNatives.refKindIsGetter(refKind));
 709         assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
 710         byte setterRefKind = (byte)(refKind + (REF_putField - REF_getField));
 711         return clone().changeReferenceKind(setterRefKind, refKind);
 712     }
 713     /** Create a name for the given class.  The resulting name will be in a resolved state. */
 714     public MemberName(Class<?> type) {
 715         init(type.getDeclaringClass(), type.getSimpleName(), type,
 716                 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
 717         initResolved(true);
 718     }
 719 
 720     /**
 721      * Create a name for a signature-polymorphic invoker.
 722      * This is a placeholder for a signature-polymorphic instance
 723      * (of MH.invokeExact, etc.) that the JVM does not reify.
 724      * See comments on {@link MethodHandleNatives#linkMethod}.
 725      */
 726     static MemberName makeMethodHandleInvoke(String name, MethodType type) {
 727         return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
 728     }
 729     static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
 730         MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
 731         mem.flags |= mods;  // it's not resolved, but add these modifiers anyway
 732         assert(mem.isMethodHandleInvoke()) : mem;
 733         return mem;
 734     }
 735 
 736     static MemberName makeVarHandleMethodInvoke(String name, MethodType type) {
 737         return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
 738     }
 739     static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) {
 740         MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual);
 741         mem.flags |= mods;  // it's not resolved, but add these modifiers anyway
 742         assert(mem.isVarHandleMethodInvoke()) : mem;
 743         return mem;
 744     }
 745 
 746     // bare-bones constructor; the JVM will fill it in
 747     MemberName() { }
 748 
 749     // locally useful cloner
 750     @Override protected MemberName clone() {
 751         try {
 752             return (MemberName) super.clone();
 753         } catch (CloneNotSupportedException ex) {
 754             throw newInternalError(ex);
 755         }
 756      }
 757 
 758     /** Get the definition of this member name.
 759      *  This may be in a super-class of the declaring class of this member.
 760      */
 761     public MemberName getDefinition() {
 762         if (!isResolved())  throw new IllegalStateException("must be resolved: "+this);
 763         if (isType())  return this;
 764         MemberName res = this.clone();
 765         res.clazz = null;
 766         res.type = null;
 767         res.name = null;
 768         res.resolution = res;
 769         res.expandFromVM();
 770         assert(res.getName().equals(this.getName()));
 771         return res;
 772     }
 773 
 774     @Override
 775     @SuppressWarnings({"deprecation", "removal"})
 776     public int hashCode() {
 777         // Avoid autoboxing getReferenceKind(), since this is used early and will force
 778         // early initialization of Byte$ByteCache
 779         return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType());
 780     }
 781 
 782     @Override
 783     public boolean equals(Object that) {
 784         return (that instanceof MemberName && this.equals((MemberName)that));
 785     }
 786 
 787     /** Decide if two member names have exactly the same symbolic content.
 788      *  Does not take into account any actual class members, so even if
 789      *  two member names resolve to the same actual member, they may
 790      *  be distinct references.
 791      */
 792     public boolean equals(MemberName that) {
 793         if (this == that)  return true;
 794         if (that == null)  return false;
 795         return this.clazz == that.clazz
 796                 && this.getReferenceKind() == that.getReferenceKind()
 797                 && Objects.equals(this.name, that.name)
 798                 && Objects.equals(this.getType(), that.getType());
 799     }
 800 
 801     // Construction from symbolic parts, for queries:
 802     /** Create a field or type name from the given components:
 803      *  Declaring class, name, type, reference kind.
 804      *  The declaring class may be supplied as null if this is to be a bare name and type.
 805      *  The resulting name will in an unresolved state.
 806      */
 807     public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
 808         init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
 809         initResolved(false);
 810     }
 811     /** Create a method or constructor name from the given components:
 812      *  Declaring class, name, type, reference kind.
 813      *  It will be a constructor if and only if the name is {@code "<init>"}.
 814      *  The declaring class may be supplied as null if this is to be a bare name and type.
 815      *  The last argument is optional, a boolean which requests REF_invokeSpecial.
 816      *  The resulting name will in an unresolved state.
 817      */
 818     public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
 819         int initFlags = (name != null && name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD);
 820         init(defClass, name, type, flagsMods(initFlags, 0, refKind));
 821         initResolved(false);
 822     }
 823     /** Create a method, constructor, or field name from the given components:
 824      *  Reference kind, declaring class, name, type.
 825      */
 826     public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
 827         int kindFlags;
 828         if (MethodHandleNatives.refKindIsField(refKind)) {
 829             kindFlags = IS_FIELD;
 830             if (!(type instanceof Class))
 831                 throw newIllegalArgumentException("not a field type");
 832         } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
 833             kindFlags = IS_METHOD;
 834             if (!(type instanceof MethodType))
 835                 throw newIllegalArgumentException("not a method type");
 836         } else if (refKind == REF_newInvokeSpecial) {
 837             kindFlags = IS_CONSTRUCTOR;
 838             if (!(type instanceof MethodType) ||
 839                 !CONSTRUCTOR_NAME.equals(name))
 840                 throw newIllegalArgumentException("not a constructor type or name");
 841         } else {
 842             throw newIllegalArgumentException("bad reference kind "+refKind);
 843         }
 844         init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
 845         initResolved(false);
 846     }
 847     /** Query whether this member name is resolved to a non-static, non-final method.
 848      */
 849     public boolean hasReceiverTypeDispatch() {
 850         return MethodHandleNatives.refKindDoesDispatch(getReferenceKind());
 851     }
 852 
 853     /** Query whether this member name is resolved.
 854      *  A resolved member name is one for which the JVM has found
 855      *  a method, constructor, field, or type binding corresponding exactly to the name.
 856      *  (Document?)
 857      */
 858     public boolean isResolved() {
 859         return resolution == null;
 860     }
 861 
 862     void initResolved(boolean isResolved) {
 863         assert(this.resolution == null);  // not initialized yet!
 864         if (!isResolved)
 865             this.resolution = this;
 866         assert(isResolved() == isResolved);
 867     }
 868 
 869     void checkForTypeAlias(Class<?> refc) {
 870         if (isInvocable()) {
 871             MethodType type;
 872             if (this.type instanceof MethodType)
 873                 type = (MethodType) this.type;
 874             else
 875                 this.type = type = getMethodType();
 876             if (type.erase() == type)  return;
 877             if (VerifyAccess.isTypeVisible(type, refc))  return;
 878             throw new LinkageError("bad method type alias: "+type+" not visible from "+refc);
 879         } else {
 880             Class<?> type;
 881             if (this.type instanceof Class<?>)
 882                 type = (Class<?>) this.type;
 883             else
 884                 this.type = type = getFieldType();
 885             if (VerifyAccess.isTypeVisible(type, refc))  return;
 886             throw new LinkageError("bad field type alias: "+type+" not visible from "+refc);
 887         }
 888     }
 889 
 890 
 891     /** Produce a string form of this member name.
 892      *  For types, it is simply the type's own string (as reported by {@code toString}).
 893      *  For fields, it is {@code "DeclaringClass.name/type"}.
 894      *  For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
 895      *  If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
 896      *  If the member is unresolved, a prefix {@code "*."} is prepended.
 897      */
 898     @SuppressWarnings("LocalVariableHidesMemberVariable")
 899     @Override
 900     public String toString() {
 901         if (isType())
 902             return type.toString();  // class java.lang.String
 903         // else it is a field, method, or constructor
 904         StringBuilder buf = new StringBuilder();
 905         if (getDeclaringClass() != null) {
 906             buf.append(getName(clazz));
 907             buf.append('.');
 908         }
 909         String name = this.name; // avoid expanding from VM
 910         buf.append(name == null ? "*" : name);
 911         Object type = this.type; // avoid expanding from VM
 912         if (!isInvocable()) {
 913             buf.append('/');
 914             buf.append(type == null ? "*" : getName(type));
 915         } else {
 916             buf.append(type == null ? "(*)*" : getName(type));
 917         }
 918         byte refKind = getReferenceKind();
 919         if (refKind != REF_NONE) {
 920             buf.append('/');
 921             buf.append(MethodHandleNatives.refKindName(refKind));
 922         }
 923         //buf.append("#").append(System.identityHashCode(this));
 924         return buf.toString();
 925     }
 926     private static String getName(Object obj) {
 927         if (obj instanceof Class<?>)
 928             return ((Class<?>)obj).getName();
 929         return String.valueOf(obj);
 930     }
 931 
 932     public IllegalAccessException makeAccessException(String message, Object from) {
 933         message = message + ": "+ toString();
 934         if (from != null)  {
 935             if (from == MethodHandles.publicLookup()) {
 936                 message += ", from public Lookup";
 937             } else {
 938                 Module m;
 939                 Class<?> plc;
 940                 if (from instanceof MethodHandles.Lookup lookup) {
 941                     from = lookup.lookupClass();
 942                     m = lookup.lookupClass().getModule();
 943                     plc = lookup.previousLookupClass();
 944                 } else {
 945                     m = ((Class<?>)from).getModule();
 946                     plc = null;
 947                 }
 948                 message += ", from " + from + " (" + m + ")";
 949                 if (plc != null) {
 950                     message += ", previous lookup " +
 951                         plc.getName() + " (" + plc.getModule() + ")";
 952                 }
 953             }
 954         }
 955         return new IllegalAccessException(message);
 956     }
 957     private String message() {
 958         if (isResolved())
 959             return "no access";
 960         else if (isConstructor())
 961             return "no such constructor";
 962         else if (isMethod())
 963             return "no such method";
 964         else
 965             return "no such field";
 966     }
 967     public ReflectiveOperationException makeAccessException() {
 968         String message = message() + ": "+ toString();
 969         ReflectiveOperationException ex;
 970         if (isResolved() || !(resolution instanceof NoSuchMethodError ||
 971                               resolution instanceof NoSuchFieldError))
 972             ex = new IllegalAccessException(message);
 973         else if (isConstructor())
 974             ex = new NoSuchMethodException(message);
 975         else if (isMethod())
 976             ex = new NoSuchMethodException(message);
 977         else
 978             ex = new NoSuchFieldException(message);
 979         if (resolution instanceof Throwable)
 980             ex.initCause((Throwable) resolution);
 981         return ex;
 982     }
 983 
 984     /** Actually making a query requires an access check. */
 985     /*non-public*/
 986     static Factory getFactory() {
 987         return Factory.INSTANCE;
 988     }
 989     /** A factory type for resolving member names with the help of the VM.
 990      *  TBD: Define access-safe public constructors for this factory.
 991      */
 992     /*non-public*/
 993     static class Factory {
 994         private Factory() { } // singleton pattern
 995         static Factory INSTANCE = new Factory();
 996 
 997         private static int ALLOWED_FLAGS = ALL_KINDS;
 998 
 999         /// Queries
1000         List<MemberName> getMembers(Class<?> defc,
1001                 String matchName, Object matchType,
1002                 int matchFlags, Class<?> lookupClass) {
1003             matchFlags &= ALLOWED_FLAGS;
1004             String matchSig = null;
1005             if (matchType != null) {
1006                 matchSig = BytecodeDescriptor.unparse(matchType);
1007                 if (matchSig.startsWith("("))
1008                     matchFlags &= ~(ALL_KINDS & ~IS_INVOCABLE);
1009                 else
1010                     matchFlags &= ~(ALL_KINDS & ~IS_FIELD);
1011             }
1012             final int BUF_MAX = 0x2000;
1013             int len1 = matchName == null ? 10 : matchType == null ? 4 : 1;
1014             MemberName[] buf = newMemberBuffer(len1);
1015             int totalCount = 0;
1016             ArrayList<MemberName[]> bufs = null;
1017             int bufCount = 0;
1018             for (;;) {
1019                 bufCount = MethodHandleNatives.getMembers(defc,
1020                         matchName, matchSig, matchFlags,
1021                         lookupClass,
1022                         totalCount, buf);
1023                 if (bufCount <= buf.length) {
1024                     if (bufCount < 0)  bufCount = 0;
1025                     totalCount += bufCount;
1026                     break;
1027                 }
1028                 // JVM returned to us with an intentional overflow!
1029                 totalCount += buf.length;
1030                 int excess = bufCount - buf.length;
1031                 if (bufs == null)  bufs = new ArrayList<>(1);
1032                 bufs.add(buf);
1033                 int len2 = buf.length;
1034                 len2 = Math.max(len2, excess);
1035                 len2 = Math.max(len2, totalCount / 4);
1036                 buf = newMemberBuffer(Math.min(BUF_MAX, len2));
1037             }
1038             ArrayList<MemberName> result = new ArrayList<>(totalCount);
1039             if (bufs != null) {
1040                 for (MemberName[] buf0 : bufs) {
1041                     Collections.addAll(result, buf0);
1042                 }
1043             }
1044             for (int i = 0; i < bufCount; i++) {
1045                 result.add(buf[i]);
1046             }
1047             // Signature matching is not the same as type matching, since
1048             // one signature might correspond to several types.
1049             // So if matchType is a Class or MethodType, refilter the results.
1050             if (matchType != null && matchType != matchSig) {
1051                 for (Iterator<MemberName> it = result.iterator(); it.hasNext();) {
1052                     MemberName m = it.next();
1053                     if (!matchType.equals(m.getType()))
1054                         it.remove();
1055                 }
1056             }
1057             return result;
1058         }
1059         /** Produce a resolved version of the given member.
1060          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1061          *  Access checking is performed on behalf of the given {@code lookupClass}.
1062          *  If lookup fails or access is not permitted, null is returned.
1063          *  Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1064          */
1065         private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass, int allowedModes,
1066                                    boolean speculativeResolve) {
1067             MemberName m = ref.clone();  // JVM will side-effect the ref
1068             assert(refKind == m.getReferenceKind());
1069             try {
1070                 // There are 4 entities in play here:
1071                 //   * LC: lookupClass
1072                 //   * REFC: symbolic reference class (MN.clazz before resolution);
1073                 //   * DEFC: resolved method holder (MN.clazz after resolution);
1074                 //   * PTYPES: parameter types (MN.type)
1075                 //
1076                 // What we care about when resolving a MemberName is consistency between DEFC and PTYPES.
1077                 // We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM
1078                 // finishes the resolution, so do TA checks right after MHN.resolve() is over.
1079                 //
1080                 // All parameters passed by a caller are checked against MH type (PTYPES) on every invocation,
1081                 // so it is safe to call a MH from any context.
1082                 //
1083                 // REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't
1084                 // participate in method selection.
1085                 m = MethodHandleNatives.resolve(m, lookupClass, allowedModes, speculativeResolve);
1086                 if (m == null && speculativeResolve) {
1087                     return null;
1088                 }
1089                 m.checkForTypeAlias(m.getDeclaringClass());
1090                 m.resolution = null;
1091             } catch (ClassNotFoundException | LinkageError ex) {
1092                 // JVM reports that the "bytecode behavior" would get an error
1093                 assert(!m.isResolved());
1094                 m.resolution = ex;
1095                 return m;
1096             }
1097             assert(m.referenceKindIsConsistent());
1098             m.initResolved(true);
1099             assert(m.vminfoIsConsistent());
1100             return m;
1101         }
1102         /** Produce a resolved version of the given member.
1103          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1104          *  Access checking is performed on behalf of the given {@code lookupClass}.
1105          *  If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
1106          *  Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1107          */
1108         public <NoSuchMemberException extends ReflectiveOperationException>
1109                 MemberName resolveOrFail(byte refKind, MemberName m,
1110                                          Class<?> lookupClass, int allowedModes,
1111                                          Class<NoSuchMemberException> nsmClass)
1112                 throws IllegalAccessException, NoSuchMemberException {
1113             assert lookupClass != null || allowedModes == LM_TRUSTED;
1114             MemberName result = resolve(refKind, m, lookupClass, allowedModes, false);
1115             if (result.isResolved())
1116                 return result;
1117             ReflectiveOperationException ex = result.makeAccessException();
1118             if (ex instanceof IllegalAccessException)  throw (IllegalAccessException) ex;
1119             throw nsmClass.cast(ex);
1120         }
1121         /** Produce a resolved version of the given member.
1122          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1123          *  Access checking is performed on behalf of the given {@code lookupClass}.
1124          *  If lookup fails or access is not permitted, return null.
1125          *  Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1126          */
1127         public MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass, int allowedModes) {
1128             assert lookupClass != null || allowedModes == LM_TRUSTED;
1129             MemberName result = resolve(refKind, m, lookupClass, allowedModes, true);
1130             if (result != null && result.isResolved())
1131                 return result;
1132             return null;
1133         }
1134         /** Return a list of all methods defined by the given class.
1135          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1136          *  Access checking is performed on behalf of the given {@code lookupClass}.
1137          *  Inaccessible members are not added to the last.
1138          */
1139         public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,
1140                 Class<?> lookupClass) {
1141             return getMethods(defc, searchSupers, null, null, lookupClass);
1142         }
1143         /** Return a list of matching methods defined by the given class.
1144          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1145          *  Returned methods will match the name (if not null) and the type (if not null).
1146          *  Access checking is performed on behalf of the given {@code lookupClass}.
1147          *  Inaccessible members are not added to the last.
1148          */
1149         public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,
1150                 String name, MethodType type, Class<?> lookupClass) {
1151             int matchFlags = IS_METHOD | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1152             return getMembers(defc, name, type, matchFlags, lookupClass);
1153         }
1154         /** Return a list of all constructors defined by the given class.
1155          *  Access checking is performed on behalf of the given {@code lookupClass}.
1156          *  Inaccessible members are not added to the last.
1157          */
1158         public List<MemberName> getConstructors(Class<?> defc, Class<?> lookupClass) {
1159             return getMembers(defc, null, null, IS_CONSTRUCTOR, lookupClass);
1160         }
1161         /** Return a list of all fields defined by the given class.
1162          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1163          *  Access checking is performed on behalf of the given {@code lookupClass}.
1164          *  Inaccessible members are not added to the last.
1165          */
1166         public List<MemberName> getFields(Class<?> defc, boolean searchSupers,
1167                 Class<?> lookupClass) {
1168             return getFields(defc, searchSupers, null, null, lookupClass);
1169         }
1170         /** Return a list of all fields defined by the given class.
1171          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1172          *  Returned fields will match the name (if not null) and the type (if not null).
1173          *  Access checking is performed on behalf of the given {@code lookupClass}.
1174          *  Inaccessible members are not added to the last.
1175          */
1176         public List<MemberName> getFields(Class<?> defc, boolean searchSupers,
1177                 String name, Class<?> type, Class<?> lookupClass) {
1178             int matchFlags = IS_FIELD | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1179             return getMembers(defc, name, type, matchFlags, lookupClass);
1180         }
1181         /** Return a list of all nested types defined by the given class.
1182          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1183          *  Access checking is performed on behalf of the given {@code lookupClass}.
1184          *  Inaccessible members are not added to the last.
1185          */
1186         public List<MemberName> getNestedTypes(Class<?> defc, boolean searchSupers,
1187                 Class<?> lookupClass) {
1188             int matchFlags = IS_TYPE | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1189             return getMembers(defc, null, null, matchFlags, lookupClass);
1190         }
1191         private static MemberName[] newMemberBuffer(int length) {
1192             MemberName[] buf = new MemberName[length];
1193             // fill the buffer with dummy structs for the JVM to fill in
1194             for (int i = 0; i < length; i++)
1195                 buf[i] = new MemberName();
1196             return buf;
1197         }
1198     }
1199 }